Performance Analysis And Digital Design Of Double-row Tapered Roller Bearings

Bearing is one of the essential parts of the train.For the axle box bearing in the high-speed train bogie,it bears the weight of the body,the impact load of the rail and the axial load on the turn,which is related to the normal operation of the whole system.It is of great significance to establish a precise mechanical calculation model,predict the fatigue life of the bearing accurately,analyze the sliding of the bearing and the heat of internal friction,and provide a certain theoretical basis for the normal and stable operation of the railway train under the high-speed condition.In this paper,a quasi-static calculation model and a quasi-dynamic calculation model are established for the double-row tapered roller bearings under the condition of "back to back" installation,and the friction power of the bearing is available on this basis.Taking the bearing of a motor car axle box as an example,the fatigue life calculation method of bearing,the quasi-dynamic characteristics of bearing and the friction power of the bearing are analyzed.Based on the development of bearing calculation program,a double-row tapered roller bearing calculation software is set up to carry out the digital design of bearings.Specific research contents are as follows:(1)Considering the centrifugal effect of the bearing and the influence of the initial clearance,based on the Python language,a quasi-static model inner ring with 5 degrees of freedom and a roller with 3 degrees of freedom is established by converting the different coordinate system for "back to back" installation of double-row tapered roller bearings.This model is applied to the axle box bearing of a high-speed train,and the load distribution of the roller and the inner ring raceway,the roller and the outer ring raceway,and the contact of the roller and the flange are obtained by using the obtained displacement solution.The load distribution characteristics of different speed and clearance are analyzed,and the three methods of calculating the fatigue life of the bearing are compared with the ISO standard calculation method,the L-P theory life calculation method and the improved L-P theory life calculation method.(2)Considering the influence of friction,lubrication and cage on the bearing,a quasi-dynamic calculation model is established.The angular velocity distribution of each rolling element,the distribution of the relative sliding velocity of the roller and the inner,the roller and outer raceway,and the contact of the roller and the flange of the bearing are obtained.The sliding of the roller and the dynamic performance of the PV value of the inner and outer ring are studied in different working conditions.(3)Based on the quasi-dynamic analysis,a friction power calculation model is established.The friction power of each rolling element in the bearing,the roller and the inner ring raceway,the roller and the outer ring raceway,the roller and the flange and the friction power of the roller and the cage are analyzed and studied,which can be used as the input and theoretical basis for the calculation of the temperature distribution inside the bearing.(4)Based on the bearing analysis model mentioned above,the bearing calculation and analysis software is developed by using the Tkinter package of the Python language and the method of object oriented programming to realize the digital design of bearing.